Abstracts 2005 - The Psychonomic Society

Posters 2056–2063 Friday Noon
appeared in the absence of a unique luminance transient. We found
that the new object benefit was maintained. In subsequent experiments,
we investigated why others have not found attentional capture
by new objects that lacked a unique transient.
(2056)
The Parting Shot: Effects of Offsets on Attentional Orienting. SHU-
CHIEH WU, NASA Ames Research Center, & ROGER W. REMING-
TON, Johns Hopkins University—Theories of attentional capture often
ascribe special status to stimuli with abrupt onset transients, attributing
this status variously to specialized attentional mechanisms (Theeuwes,
1994; Yantis & Hillstrom, 1994) or activation of the saccade system
(Wu & Remington, 2003). However, onset properties apparently do
not tell the whole story. It has also been observed that the magnitude
and time course of capture and spatial cuing is affected by whether or
not the abruptly onset cue offsets prior to the target. This is a curious
result that seems disconnected from current accounts that attribute
capture to salience, new objects, or top-down contingencies. Here, we
report experiments that examine whether the offset effect is attributable
to mechanisms of spatial attention, saccadic eye movements, or
changes in phasic alertness.
(2057)
One Plus One Equals One: The Effects of Merging on Object Files.
STEPHEN R. MITROFF, Duke University, & BRIAN J. SCHOLL &
KAREN WYNN, Yale University—A critical task in visual processing
is keeping track of objects as the same persisting individuals over
time, and these operations can be assessed in terms of the effects of
various manipulations on mid-level object file representations. Here,
we explore perhaps the most important principle of object persistence:
Objects must maintain a single unified boundary over time (the cohesion
principle). We do so by measuring object-specific preview benefits
(OSPBs), wherein a preview of information on a specific object
speeds the recognition of that information at a later point, when it appears
again on the same object. Object files were dramatically affected
when two objects smoothly merged into one: The information
from only one object survived this cohesion violation to produce an
OSPB (whereas OSPBs from both original objects remained in control
displays without cohesion violations). These results demonstrate
the power of the cohesion principle in the maintenance of mid-level
visual representations.
(2058)
What Do We Learn From Binding Features? Evidence for Multilevel
Feature Integration. LORENZA S. COLZATO, Leiden University,
ANTONINO RAFFONE, University of Sunderland, & BERNHARD
HOMMEL, Leiden University—Four experiments were conducted to
investigate the relationship between the binding of visual features (as
measured by their aftereffects on subsequent binding) and the learning
of feature conjunction probabilities. Both binding and learning effects
were obtained, but they did not interact. Interestingly, (shape–color)
binding effects disappeared with increasing practice, presumably due
to the fact that only one of the features involved was task relevant.
However, this instability was observed only for arbitrary combinations
of simple geometric features, but not for real objects (colored pictures
of a banana and strawberry), where binding effects were strong and
practice resistant. Findings are interpreted in a neurocognitive framework
that makes a distinction between integration at low-level feature
maps, short-term acquisition of frequency-based expectations, and
Hebbian learning of object representations.
(2059)
Attention Degrades and Enhances Visual Temporal Resolution.
JEFFERY R. NICOL, SCOTT WATTER, & DAVID I. SHORE, Mc-
Master University—Relative to the effects of attention on spatial resolution,
a paucity of research has investigated the effect of attention
on temporal aspects of perception. In the present experiments, observers
made temporal order judgments reporting, in separate exper-
78
iments, either where the first of two stimuli was presented or what it
was. Here, we demonstrate both an improvement and a decrement in
temporal precision on the where and what tasks, respectively, and
argue for qualitatively different effects of attention on the dorsal and
ventral visual processing streams.
(2060)
Effects of Distractor Size on Interference and Negative Priming:
Comparison Between Shape and Phoneme Selection Tasks. JUN-
ICHI NAGAI, University of the Sacred Heart, Tokyo, & YUKI
KOBAYASHI, University of Tokyo—The effects of distractor size on
interference and negative priming were investigated to examine the relation
between these two phenomena. We compared two tasks (shape
vs. phoneme selection) using the same letter stimuli. In Experiment 1,
where the participants judged whether the target letter had a rectilinear
or a curvilinear shape (shape task), small-sized distractors produced
both interference and negative priming. However, in Experiment
2, where the participants judged whether the target letter was a
vowel or a consonant (phoneme task), small distractors produced interference,
but not negative priming. The results suggest that negative
priming depends on the behavioral goal of the current experimental
task (see also Tipper, Weaver, & Houghton, 1994), whereas distractor
interference reflects several processing levels of the distractor stimuli.
(2061)
Examining Negative and Perceptual Priming Using a Go/No-Go
Same/Different Task. EDDY J. DAVELAAR, University of Maryland,
College Park, CHRISTOPH T. WEIDEMANN, Indiana University,&
DAVID E. HUBER, University of Maryland, College Park (sponsored
by David E. Huber)—In a typical negative priming paradigm, ignored
stimuli are difficult to respond to on subsequent trials. In contradiction
to this finding, Weidemann, Huber, and Shiffrin (2005) observed
a bias to respond with ignored words in a perceptual identification
task. Attempting to reconcile these differences, we developed a new
paradigm that combines perceptual and response priming within a single
experiment. This was achieved with a same/different task (is the
target word the same as the cue word) with go/no-go responding (e.g.,
go only on different trials). Because only some words are responded
to on trial n, this allows measurement of response priming on trial n +1.
Because determination of same versus different is inherently a perceptual
task, RTs include perceptual priming effects. Our results reveal
both a general response readiness effect and an item-specific effect
with facilitation for primed cues but deficits for primed targets.
(2062)
Schematic Activation Influences Accuracy and Confidence in
Change Blindness Tasks. SHARON L. HANNIGAN, ALAN SEARLE-
MAN, EVAN SLATER, & MEREDITH A. PRIDGEN, St. Lawrence
University—This study examined the effects of attention on participants’
confidence and overall accuracy in a visual change detection
task. Employing a within-subjects design, 46 participants attended to
either a featural level (counting the number of objects that contained
either of two colors) or a semantic level (generating a name to describe
the theme of the objects) when viewing a photographed set of 10–13
semantically related objects. The results indicated that participants
were more likely to correctly claim to have noticed a semantically related
or unrelated addition of an object than either a color change or
no change. A task � type of change interaction showed that participants
were more confident about nonsemantically related additions
during the theme generation task but were more confident seeing
color changes during the color count task. When asked to identify the
specific change observed, participants were most accurate in detecting
nonsemantically related additions.
(2063)
Priority Setting Modulates Allocation of Object-Based Attention.
GARY C.-W. SHYI, HSING-YI HSIEH, & YUAN-CHI TSENG, National
Chung Cheng University—One main source of evidence for